18 research outputs found
Automatic Tuning of Wind Tubrine controller
No full textThe energy demand in current times has increased greatly in last few years. This increasing demand calls for a sustainable and clean energy resource that would reduce the load on non-renewable resources. Wind energy is a renewable resource which is harnessed by mankind from an ancient era. So as to meet this increasing energy demands, innovation in the field of wind energy is required.A wind turbine generates electricity but achieving optimal power is a difficult task. In this case, the optimal power is defined as maximum power produced but at the constraints that the fatigue loading of the wind turbine structure should be as minimum as possible. Also, the wind turbine parameters such as rotor speed and pitch activity should be in a safe operational region. The problem in controlling wind turbines is that they work in a highly uncertain environment where managing so many factors at the same time are difficult. Optimal control of wind turbine has helped in achieving maximum power with-in safe working limits. Due to high uncertainty in the operating conditions of a wind turbine, it is quite a daunting task to find optimal gains for a wind turbine controller.This thesis focuses on achieving optimal gain parameters for wind turbine controller by using an algorithm from machine learning community. In this thesis the problem is formulated as a supervised learning problem where input-output mapping has to be predicted. For this purpose, GPRT is used. The reason behind using GPRT is it takes fewer number of measurements to give good prediction compared to others. The property of GPRT where it deals with uncertain and non linear data with ease, making it a good choice for predicting wind turbine controller gains.The second part of this thesis contains optimisation of the surrogate model achieved by performing regression. The optimisation is done by Monte Carlo Maximum distribution and improved results were generated by applying sequential sampling to this algorithm. This helps us to get a likelihood of optimal gains where the wind turbine gives out rated power with minimal fatigue loads, pitch activity and least deviation of rotor speed from rated.The results obtained from the likelihood was tested for different operational wind speed and also tested for Extreme Operating Gusts as part of disturbance rejection and compared to current parameter used.The comparison shows considerable improvement in the fatigue loads and pitch activity with having improvement in power production. In second case study, more parameters were predicted and optimised using the same algorithm so that the potential of this algorithm can be estimated. This was also performed successfully which proves that this technique can successfully be used to solve higher dimensional problems of wind turbine control.Mechanical Engineering | Systems and Contro
Misspelled Author Name in the Article by Neogi et al (Arthritis Rheumatol, October 2015)
No full textIncorrect Disclosure Information Added for Author Neogi in the Article by Choi et al (Arthritis Rheumatol, November 2018)
No full textClade C HIV-1 isolates circulating in Southern Africa exhibit a greater frequency of dicysteine motif-containing Tat variants than those in Southeast Asia and cause increased neurovirulence
Get PDFabstract: Background: HIV-1 Clade C (Subtype C; HIV-1C) is responsible for greater than 50% of infections worldwide. Unlike clade B HIV-1 (Subtype B; HIV-1B), which is known to cause HIV associated dementia (HAD) in approximately 15% to 30% of the infected individuals, HIV-1C has been linked with lower prevalence of HAD (0 to 6%) in India and Ethiopia. However, recent studies report a higher prevalence of HAD in South Africa, Zambia and Botswana, where HIV-1C infections predominate. Therefore, we examined whether Southern African HIV-1C is genetically distinct and investigated its neurovirulence. HIV-1 Tat protein is a viral determinant of neurocognitive dysfunction. Therefore, we focused our study on the variations seen in tat gene and its contribution to HIV associated neuropathogenesis. Results: A phylogenetic analysis of tat sequences of Southern African (South Africa and Zambia) HIV isolates with those from the geographically distant Southeast Asian (India and Bangladesh) isolates revealed that Southern African tat sequences are distinct from Southeast Asian isolates. The proportion of HIV - 1C variants with an intact dicysteine motif in Tat protein (C30C31) was significantly higher in the Southern African countries compared to Southeast Asia and broadly paralleled the high incidence of HAD in these countries. Neuropathogenic potential of a Southern African HIV-1C isolate (from Zambia; HIV-1C(1084i)), a HIV-1C isolate (HIV-1(IndieC1)) from Southeast Asia and a HIV-1B isolate (HIV-1(ADA)) from the US were tested using in vitro assays to measure neurovirulence and a SCID mouse HIV encephalitis model to measure cognitive deficits. In vitro assays revealed that the Southern African isolate, HIV-1C(1084i) exhibited increased monocyte chemotaxis and greater neurotoxicity compared to Southeast Asian HIV-1C. In neurocognitive tests, SCID mice injected with MDM infected with Southern African HIV-1C(1084i) showed greater cognitive dysfunction similar to HIV-1B but much higher than those exposed to Southeast Asian HIV - 1C. Conclusions: We report here, for the first time, that HIV-1C from Southern African countries is genetically distinct from Southeast Asian HIV-1C and that it exhibits a high frequency of variants with dicysteine motif in a key neurotoxic HIV protein, Tat. Our results indicate that Tat dicysteine motif determines neurovirulence. If confirmed in population studies, it may be possible to predict neurocognitive outcomes of individuals infected with HIV-1C by genotyping Tat.This electronic version of this article is the complete one and can also be found online at: http://www.retrovirology.com/content/10/1/6
Health vlogger-viewer interaction in chronic illness management
No full textHealth video blogs (vlogs) allow individuals with chronic illnesses to share their stories, experiences, and knowledge with the general public. Furthermore, health vlogs help in creating a connection between the vlogger and the viewers. In this work, we present a qualitative study examining the various methods that health vloggers use to establish a connection with their viewers. We found that vloggers used genres to express specific messages to their viewers while using the uniqueness of video to establish a deeper connection with their viewers. Health vloggers also explicitly sought interaction with their viewers. Based on these results, we present design implications to help facilitate and build sustainable communities for vloggers. Author Keywords Health vlogs; YouTube; video blogging; chronic illnes
Author Correction: Analyses of HIV-1 integrase sequences prior to South African national HIV-treatment program and availability of integrase inhibitors in Cape Town, South Africa
No full textA correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.</jats:p
Fracture of neck of femur with fracture of posterior column of acetabulum: a rare case of floating hip
Get PDFInjuries around the hip joint are one of the most common orthopedic injuries and these types of injuries are grossly debilitating until treated properly. Simultaneous occurrence of fracture of proximal femur with fracture of ipsilateral acetabulum or pelvis is termed as floating hip injury. These injuries are very rare, only to be found 1 in 10,000 as well as there is lack of literature support regarding proper treatment protocol. Here we are going to present a case of fracture of neck of left femur along with fracture of left acetabulum in a 45 years old male undergone road traffic accident.
Necrotizing fasciitis caused by Pseudomonas aeruginosa: a rare case report and recent concepts in diagnosis and management
Get PDFNecrotizing fasciitis caused by Pseudomonas aeruginosa is an extremely rare and life threatening bacterial soft tissue infection. Here we report a case study of fully established necrotizing fasciitis associated with monomicrobial pseudomonas infection in a 34 years old male. The patient presented with painful, necrosed areas of skin and soft tissue over right gluteal region which rapidly progressed to right upper back. Aggressive supportive measures and early debridement lead to a full recovery with no functional deficits
The 2010 American College of Rheumatology/European League Against Rheumatism classification criteria for rheumatoid arthritis: Phase 2 methodological report
No full textFull author list omitted for brevity. For the full list of authors, see article.OBJECTIVE: The American College of Rheumatology and the European League Against Rheumatism have developed new classification criteria for rheumatoid arthritis (RA). The aim of Phase 2 of the development process was to achieve expert consensus on the clinical and laboratory variables that should contribute to the final criteria set. METHODS: Twenty-four expert RA clinicians (12 from Europe and 12 from North America) participated in Phase 2. A consensus-based decision analysis approach was used to identify factors (and their relative weights) that influence the probability of "developing RA," complemented by data from the Phase 1 study. Patient case scenarios were used to identify and reach consensus on factors important in determining the probability of RA development. Decision analytic software was used to derive the relative weights for each of the factors and their categories, using choice-based conjoint analysis. RESULTS: The expert panel agreed that the new classification criteria should be applied to individuals with undifferentiated inflammatory arthritis in whom at least 1 joint is deemed by an expert assessor to be swollen, indicating definite synovitis. In this clinical setting, they identified 4 additional criteria as being important: number of joints involved and site of involvement, serologic abnormality, acute-phase response, and duration of symptoms in the involved joints. These criteria were consistent with those identified in the Phase 1 data-driven approach. CONCLUSION: The consensus-based, decision analysis approach used in Phase 2 complemented the Phase 1 efforts. The 4 criteria and their relative weights form the basis of the final criteria set
